The present invention relates to a drum, and more particularly relates to improvement in mechanical strength of a drum such as a marching drum which requires high pitch tuning.
Typical examples of such a drum are disclosed in U.S. Pat. No. 4,448,105 and 4,869,146 as well as in Japanese Patent Publication Sho. 62-38710. In general, one or two drum heads are coupled to open ends of a hollow cylindrical shell which is made of wood or fiber reinforced plastic (FRP) material via several coupling members. More specifically, a suspension ring is attached to one open end of the shell and coupled, via several fastener bolts, to a counterhoop which is inserted over the suspension ring while holding a drum head in tension over the open end of the shell. The shell is also associated, near the other open end thereof, with the pair of suspension ring and counterhoop. The opposite suspension rings are coupled to each other via long tubes which are arranged along the circumference of the shell substantially at equal intervals. Accordingly, the shell is clamped between the pair of suspension rings (and counterhoops) connected to each other by the intervening long tubes.
For tuning of the drum, the fastener bolts are turned to adjust tension on the drum head. When the fastener bolts are turned to increase the tension on the drum head, the opposite suspension rings are forced to move away from each other and the intervening long tubes are subjected to tension. Whereas, when the fastener bolts are turned to decrease the tension on the drum head, the opposite suspension rings move toward each other and the long tubes are released from tension.
As stated above, the shell is clamped between the suspension rings connected to each other by the intervening long tubes and there is no direct mechanical connection between the coupling members and the shell. So, when the long tubes are subjected to repeated mechanical deformation for the purpose of drum tuning, accumulated structural fatigue tends to breakage of the long tubes. The higher is the tension on the drum head, the more frequent and significant is such breakage of the long tubes. Such vulnerable reaction of the long tubes against mechanical deformation is believed to be caused by absence of any substantial mechanical connection between the coupling members and the shell of the drum.